Erpur Snær Hansen, director of ecological research at the South Iceland Nature Centre, has been investigating the puffin population of the Westman Islands since 2007. If surface sea temperatures remain at current levels or higher, Hansen says, the entire puffin population of south and west Iceland will disappear in the next 10 to 20 years

As Earth Day turns 45, share your story about the natural or urban landscape you want to save. Here, Nate McDowell, a tree physiologist in New Mexico, explains how a warming climate is irreversibly altering an ancient ecosystem.